Add breeze theme and dolphin

modules/theme/default.nix

@@ -0,0 +1,52 @@
+{ self, config, pkgs, ... }: {
+  environment.systemPackages = with pkgs; [
+    qt5ct
+    breeze-qt5
+    breeze-gtk
+    breeze-icons
+  ];
+
+  environment.variables = {
+    "QT_QPA_PLATFORMTHEME" = "qt5ct";
+  };
+
+  home-manager.users.${config.main-user} = {
+    home = {
+      file.".icons/default/index.theme".text = ''
+        [Icon Theme]
+        Inherits=breeze_cursors
+      '';
+    };
+
+    xdg.configFile = {
+      # fixes dolphin background colors
+      "kdeglobals".source = "${pkgs.breeze-qt5}/share/color-schemes/BreezeDark.colors";
+
+      "qt5ct/qt5ct.conf".text = ''
+        [Appearance]
+        style=Breeze
+
+        # Cantata misbehaves without color overrides. This overrides the breeze colors with the
+        # exact same colors.
+        color_scheme_path=${./breeze-dark-colors-override.conf}
+        custom_palette=true
+      '';
+    };
+
+    gtk = {
+      enable = true;
+      theme = {
+        package = pkgs.breeze-gtk;
+        name = "Breeze-Dark";
+      };
+      iconTheme = {
+        package = pkgs.breeze-icons;
+        name = "breeze-dark";
+      };
+      cursorTheme = {
+        package = pkgs.breeze-gtk;
+        name = "breeze_cursors";
+      };
+    };
+  };
+}